Lung ventilating equipment



United States Patent 3,266,488 LUNG VENTILATING EQUHPMENT Christian B. Andreasen, New Hope, Pa., assignor to Air- Shields, inc, Hatboro, Pa, a corporation of Delaware Filed Jane 10, 1963, Ser. No. 286,587

6 Claims. (6]. 128-29) This invention relates to lung ventilating equipment and is particularly concerned with apparatus adapted to function 50 as to induce artificial respiration or so as to assist a patients respiratory eifort.

The invention is especially concerned with the type of equipment or apparatus which comprises a self-contained unit, i.e., incorporates not only the equipment tor delivering the breathing gases to the patient but also the power means such as a blower, for developing pressure by means of which the apparatus is operated.

Still further the invention is concerned with the type of ventilating or respiration apparatus incorporating an aerosol or humidiiication device by which moisture is introduced into the gas delivered to the patient, such humidification device also comprising a part of the self-contained unit.

In apparatus of the kind referred to above, it is a specific object of the invention to provide a number of improvements by which the apparatus is rendered safer, more reliable and more fool-proof than prior equipment, thereby making possible long continued use of the apparatus in the case of patients experiencing protracted periods of inadequate self-inspirational elfort.

It is also an object of the invention to make provision for the important functions of the automatic timing of the patients breathing, together with an override or trigger device operating by the patients own inspirational effort, While at the same time simplifying the equipment and making possible the attainment of these functions with a minimum of parts and controls.

In accordance with another aspect of the invention, provision is made for indirectly warming the water in the humidilication device by means of a current of warmed air developed by the blower included in the equipment.

In connection with still another aspect of the invention it is mentioned that equipment of this type is frequently associated with the patient either by use of a mask or by connection with the patients trachea. The arrangement of the invention makes possible substantially unimpeded breathing by a patient either throughthe mask or connection to the trachea, even in the event of failure of the power or control system for the equipment.

How the foregoing objects and advantages are attained will appear more fully from the following description referring to the accompanying drawing which diagrammatically illustrates a system constructed according to the present invention and in which:

FIGURE 1 is a representation of the apparatus with various valves and parts in the positions occupied during inspiration by the patient as effected by the automatic control provided;

FIGURE 2 is a view similar to FIGURE 1 but illustrating the position of valves and parts during expiration by the patient as effected by the automatic control provided; and

FIGURE 3 is a fragmentary view similar to certain parts of FIGURES 1 and 2 but illustrating the position of those parts assumed in response to a voluntary inspirational eifort by the patient.

Turning now to the drawing, the patients circuit or system includes the conduit means, portions ofwhich are indicated by the numeral 4. A mask 5 or equivalent is provided at one end of this system for association with the patient, the inspiratory as well as the expiratory gases both passing through this mask. An aerosol or humidificaice tion device indicated generally by the numeral 6 is inserted in the conduit means 4 to provide for the introduction of moisture into the air breathed by the patient. This device advantageously contains a reservoir of water, the level of which is indicated at W, together with a rotative atomizing element 7 which may be of the general type disclosed in copending application Serial No. 107,756, filed May 4, 1961, of Christian B. Andreasen, Harold Kenneth Richter and George H. Stoner.

As seen toward the central portion of FIGURES 1 and 2, the equipment includes a chamber 8, which may advantageously be provided by a transparent cylindrical wall, with end closures. Within the chamber 8 is a bellows 9 supported from the wall of the chamber 8 by the Wall 10 which also closes the upper end of the bellows, except for ports to be described. The bottom of the bellows is closed by the wall 11. The patients circuit or conduit 4 is connected with the interior of the bellows through the port 12 which is provided with a check valve 1-3 arranged to prevent flow of gas from the conduit 4 into the bellows but to provide free egress of air from the interior of the bellows into the conduit 4. The topwall of the bellows 10 is also provided with another port 14 communicating through a filter 15 with the atmosphere as by means of ports indicated at 16. Port 14 is provided with a check valve 17 which is arranged to prevent exhaust of air from the interior of the bellows to atmosphere but to provide free ingress of atmospheric air through the filter into the interior of the bellows.

The chamber surrounding the bellows 9 is placed in connection with the source of fluid presure such as a motorblower unit generally indicated at 18, a duct '19 being provided for connecting this uni-t with the bellows chamber. A check valve 20 serves to block flow of air from the bellows chamber back into the duct 19 but to permit free ingress of air from the duct into the bellows chamber.

A ir may be exhausted from the bellows chamber through a port 21 which is provided with valve 22, this valve being carried by a flexible diaphragm 23 associated with a pressure chamber 24. When the valve 22 is open (see FIGURE 2) air may be discharged from the bellows chamber to atmosphere.

The duct 19 may be blocked or closed by means of a valve 25, this valve being shown in open position in FIG- UR=ES 1 and 3 and in closed position in FIGURE 2. The valve is adapted to be operated by a solenoid 2 6 which is connected through leads 27 with a timer mechanism 28, for instance an electronic circuit such as a multi-vibrator of well-known type.

When the timer operates to open the valve 25 as shown in FIGURE 1, air under pressure flows from the blower 18 through the duct 19 past valve 20 into the bellows chamber 8. At the same time, through the control line 29 air under pressure is introduced into the pressure device 24 to thereby retain valve 22 closed. In this condition the air introduced into the bellows chamber acts on the bellows to collapse it and thereby force air out through the port 12 and past valve 13 and through duct 4 to the patient. This pressure developed in the bellows also acts to close the check valve 17. Moreover, during inspiration by the patient, the exhaust port 30 is closed by means of the exhaust valve 31 which is mounted on flexible diaphragm 32 associated with the pressure device 33 which receives fluid under pressure from the duct 19 by means of the duct 34. In this way as will be clear from comparison of FIGURES 1 and 2, when the main control valve 25 is open the pressure from the blower not only acts to callapse the bellows 9 and deliver air to the patient, but also operates on the valve 31 to close the exhaust port 30 and thus prevent loss of air through the exhaust port.

At the conclusion of inspiration, the timer 28 operates the solenoid 26 to close valve 25 (see FIGURE 2), whereupon an expiratory phase occurs during which the expiratory gases in. the. conduit means 4 adjacent the patient will flow therefrom to atmosphere through the port 30 (see FIGURE 2). Upon expiration the pressure in the control line 34 is relieved through the exhaust passage 35 which is also controlled by the valve 25, this exhaustpassage being closed when the main valve is in its upper oropen position (see FIGURE 1) and being open when the main valve is in its lower or closed position (see FIGURE 2). I

Similarly during the expiratory phase of the breathing cycle pressure is exhausted from the pressure device 24, so that the valve 22 may readily open by the bleed-off of pressure through the control line 29 into the duct 19 and from there through the exhaust passage 35 which at that time is open to atmosphere as already noted. In view of this the bellows 9 may at that time expand and thereby expell air from the bellows chamber through the port 21 to atmosphere. The expansion of the bellows is desirably effected as a result of its own weight, which may be augmented by weighting of the lower wall 11. In this way, the bellows expands during the expiration by the patient and then is again ready for the inspiration stroke, i.e., the collapsing stroke effected by introduction of pressure into the chamber 8. p A valve diagrammatically indicated at 36 may be adjusted to vary the flow of air through the duct 19 into the bellows chamber and thereby regulate the inspiration efiect of the apparatus. vIt is of course also contemplated that the duration of the inspiration and also of the expiratory phase may be regulated by the adjustment of the circuits of the timing mechanism in a manner which is well known with multivibrator or other electronic timing circuits.

The operation described above provides for automatic inspiration by the patient under timer control. The equipmen of the invention further provides for response in accordance with inspirational eifort made by the patient at any point during the expiratory phase. This is accomplished by the fluid pressure responsive device 37 having a control connection 38 extended therefrom for communication with the patients circuit or conduit means 4. Within the device 37 is a flexible diaphragm 39 carrying a plunger 40 projecting at the bottom in position to operate switch 41 which is connected by lead 42 with the timer mechanism to thereby trigger the mechanism to operate the solenoid 26 in the sense to open valve 25. The triggered position of these parts is indicated in FIGURE 3 and from this figure it will also be noted that the switch 41 also serves to energize a circuit 43 containing a signal lamp 44 by which a visual indication will be given of the fact that the patient has manifested an inspirational effort. According to the foregoing the equipment of the invention provides not only for the automatic cycling of the patients breathing but also provides for operation in the manner of a breathing assistor, according to which inspirational effort by the patient will trigger the mechanism to bring about the feed of air through the conduit means 4 to the patient.

By arranging the control pressure supply passages 29 and 34 and the exhaust passage 35 in the manner described and illustrated, it will be noted that the main control valve 25 controls not only the flow of air into the bellows chamber 8 but also the supply of air to the control device 24 and 33 for valves 22 and 31, and still further provides for bleed-off of pressure from the control devices 24 and 33 through the exhaust passage 35.

It may further be noted that the arrangement of the check valves 13 and 17 which are associated with the interior of the bellows and with the conduit means 4 are arranged so that in the event of failure of the apparatus, even of the action of the bellows 9, the patients breathing still would not be substantially impeded, it being noted that 4 inspiration by the patient may occur through the filter 15 and the interior of the bellows. In such a case the patients inspiration will act to open both of the check valves 13 and 17 and thus provide a channel of fresh air through the bellows space.

In the lower portion of the humidification unit, below the water bath is a chamber 47 having balfles or the like therein such as represented by the numeral 45, this chamber also being open to atmosphere at 46. The chamber is supplied with air through the connection 48 which extends for communication with the duct 19. It will be noted that the blower motor 18a and the blower fan 18b are positioned within the blower unit 18 in such manner that the air handled by the fan passes over the motor for cooling purposes. Thus it is warmed air which is delivered to the chamber 47 at the bottom of the humidifier and this tends to warm the water in the humidifier and thereby enhances the humidifying action.

This use of the warm air from the blower enhances the humidification without delivery of air which has passed over the blower motor into the patients circuit. Moreover the arrangement as described just above also has the advantage that the warming effect of the water in the humidifier continues regardless of whether the main shutoff valve in the duct 19 is opened or closed.

I claim:

1. Lung ventilating equipment comprising a patients circuit including means adapted to be associated with a patient for supply of breathing gas and .further including a bellows collapsible to develop pressure in the patients circuit to effect inspiration by the patient, a chamber surrounding the bellows, power means for introducing pres sure into said chamber to effect collapse of the bellows and inspiration by the patient, an expiration valve associated with the patients circuit for discharge of expiratory gas, valve means for blocking or passing the pressure supplied by the power means into said chamber, an exhaust valve for relieving pressure in said chamber when the bellows expands, said expiration valve and said exhaust valve having pressure responsive devices associated therewith for holding those valves closed during the introduction of pressure thereto, pressure supply passages controlled by said valve means for the introduction of pressure to said pressure responsive devices when said valve means passes pressure into said chamber; portage for venting said pressure supply passages and means con trolled by said valve means to open said portage when the valve means is operated to block delivery of pressure into said chamber and thereby provide for opening of both the expiration valve and the exhaust valve during expansion of the bellows and to close said portage when the valve means passes passage into the chamber.

2; A construction according to claim 1 and further including a fluid pressure device responsive to voluntary inspirational effort by the patient to operate the valve means to close said venting means and to pass pressure into said chamber to effect inspiration by the patient.

3. Lung ventilating equipment comprising a patients circuit including means adapted to be associated with apatient for supply of breathing gas and further including a bellows collapsible to develop pressure in the patients circuit to efiect inspiration by the patient, a chamber surrounding the bellows, power means ior developing air pressure, a conduit for delivering air under pressure [from the power means to said chamber to eflect collapse of the bellows and inspiration by the patient, an expiration valve associated with the patients circuit for discharge of expiratory gas, valve means for blocking or passing the air under pressure in said conduit, a check valve for blocking flow from said chamber into said conduit when the bellows expands, an exhaust valve for relieving pressure in said chamber when the bellows expands, said expiration valve and said exhaust valve having pressure responsive devices associated therewith for holding those valves closed during'the introduction of pressure thereto, pressure supply passages controlled by said valve means for the introduction of pressure to said pressure responsive devices when said valve means passes pressure into said chamber, portage for venting said pressure supply passages to atmosphere and means connected to said valve means to open said portage when the valve :means blocks delivery of pressure into said chamber and thereby provide for opening of both the expiration valve and the exhaust valve during expansion of the bellows and to close said portage when the valve means passes pressure to said chamber, a solenoid for actuating the valve means, timer circuit means connected to the solenoid to provide for timed operation of the solenoid to actuate the valve means to provide a period of inspiration and also an expiratory pause, a fluid pressure device in said patients circuit operable in response to voluntary inspirational effort by the patient, and means circuit controlled by said pressure device to operate said valve means to pass air into said chamber at any time during said expiratory pause.

4. Lung ventilating equipment comprising conduit means adapted to be associated with a patient for supply of breathing gas, a gas blower including a blower motor and a blower fan for developing pressure to eflect delivery of breathing gas from the circuit means to the patient, the blower having a gas delivery duct with valve means therein for blocking delivery of gas from the blower, control means for opening and closing said valve means to provide for inspiration by the patient and for an expiratory pause, a humidifier associated with said conduit means for lmmidifying gas delivered to the patient and including a reservoir for the humidifyinig water, the humidifier turther having an air chamber below the reservoir, and an air supply connection for said chamber connected with the gas delivery duct of the blower in advance of the valve means therein said blower motor and said blower fan being relatively arranged to provide for flow of air over the motor and into the duct, and to thereby continuallly supply warm air to the chamber below the water reservoir in the humidifier regardless of whether said valve means is open or closed.

5. Lung ventilating equipment comprising conduit means adapted to be associated with a patient for supply of breathing gas, a gas blower for developing pressure to effect delivery of breathing gas from the conduit means to the patient, an expiration valve associated with the conduit means for discharge of expiratory gas and having a pressure responsive device for effecting closure of the expiration valve, a pressure supply passage for said device, an air supply valve means for blocking delivery of gas from the blower, timer mechanism connected With said valve means and providing for timed operation of the valve means to establish a period of inspiration and also an expiratory phase, said pressure supply passage being pneumatically connected to said gas blower and controlled by said valve means to provide for timed delivery of pressure through said pressure sup-ply passage to said pressure responsive device when said valve means is open, thereby providing for closure of the expiration valve during delivery of breathing gas to the patient, a port for venting said pressure supply passage, means associated with said valve means and controlled thereby to open the port to vent said pressure supply passage when the valve means is conditioned to block delivery of gas from the blower, and thereby provide for timed opening of the expiration valve during the expiratory phase and to close the port when the valve means is opened, and a fluid pressure device responsive to voluntary inspiration effort by the patient and including means for opening the air supply valve means at all times during said expiratory phase thereby overriding the timer mechanism and to provide for development of pressure to eflect delivery of breathing gas to the patient.

6. Lung ventilating equipment comprising conduit means adapted to be associated with a patient for supply of breathing gas, a gas blower for developing pressure to effect delivery of breathing gas from the conduit means to the patient, an expiration valve associated with the conduit means for discharge of expiratory gas and having a pressure responsive device for effecting closure of the expiration valve, a pressure supply passage for said device, valve means for blocking delivery of gas from the blower, a solenoid for actuating the valve means, timer circuit means connected to the solenoid to provide for timed operation of the solenoid to actuate the valve means to provide a period of inspiration and also an expiratory phase, said pressure supply passage being pneumatically connected to said gas blower and controlled by said valve means to provide for delivering of pressure to said pressure responsive device when said valve means is open, thereby providing for closure of the expiration valve during delivery of breathing gas to the patient, a port for venting said pressure supply passage, means associated with said valve means and controlled thereby to open the port to vent said pressure supply passage when the valve means is operated to block delivery of gas from the blower and to close the port when the valve means is opened, and thereby provide for opening of the expiration valve during the expiratory phase, a fluid pressure responsive device, an air supply passage interconnecting said fluid pressure responsive device with said conduit means, said fluid pressure responsive device being responsive to a voluntary inspirational effort by the patient, and means controlled by said pressure responsive device to open the air supply valve means at all times during said expiratory phase thereby overriding the timer mechanism and to provide for development of pressure to effect delivery of breathing gas to the patient.

References Cited by the Examiner UNITED STATES PATENTS 2,391,877 1/1946 Cahan 137-163 X 2,774,346 12/ 1956 Halliburton 128-29 2,830,580 4/1958 Saklad et a1. 128-29 2,972,345 2/1961 Spigel 128-29 3,071,131 1/1963 Johannisson et al. 128-29 3,101,708 8/1963 Perry et al. 128-29 OTHER REFERENCES British Journal of Anaesthesia (1958), vol. 30, A Volume Controlled Piatient-Cyoled Respiration for Adults, J. R. Greer and I. Donald, pp. 32-36.

RICHARD A. GAUDET, Primary Examiner. C. F. ROSENBAUM, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,266,488 August 16, 1966 Christian B. Andreasen It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 52, for "passage" read pressure Signed and sealed this 8th day of April 1969.

"SEAL) Lttest:

idward M. Fletcher, Ir.

Lttesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. LUNG VENTILATING EQUIPMENT COMPRISING A PATIENT''S CIRCUIT INCLUDING MEANS ADAPTED TO BE ASSOCIATED WITH A PATIENT FOR SUPPLY OF BREATHING GAS AND FURTHER INCLUDING A BELLOWS COLLAPSIBLE TO DEVELOP PRESSURE IN THE PATIENT''S CIRCUIT TO EFFECT INSPIRATION BY THE PATIENT, A CHAMBER SURROUNDING THE BELLOWS, POWER MEANS FOR INTRODUCING PRESSURE INTO SAID CHAMBER TO EFFECT COLLAPSE OF THE BELLOWS AND INSPIRATION BY THE PATIENT, AN EXPIRATION VALVE ASSOCIATED WITH THE PATIENT''S CIRCUIT FOR DISCHARGE OF EXPIRATORY GAS, VALVE MEANS FOR BLOCKING OR PASSING THE PRESSURE SUPPLIED BY THE POWER MEANS INTO SAID CHAMBER, AN EXHAUST VALVE FOR RELIEVING PRESSURE IN SAID CHAMBER WHEN THE BELLOWS EXPANDS, SAID EXPIRATION VALVE AND SAID EXHAUST VALVE HAVING PRESSURE RESPONSIVE DEVICES ASSOCIATED THEREWITH FOR HOLDING THOSE VALVES CLOSED DURING THE INTRODUCTION OF PRESSURE THERETO, PRESSURE SUPPLY PASSAGES CONTROLLED BY SAID VALVE MEANS FOR THE INTRODUCTION OF PRESSURE TO SAID PRESSURE RESPONSIVE DEVICES WHEN SAID VALVE MEANS PASSES PRESSURE INTO SAID CHAMBER; PORTAGE FOR VENTING SAID PRESSURE SUPPLY PASSAGES AND MEANS CONTROLLED BY SAID VALVE MEANS TO OPEN SAID PORTAGE WHEN THE VALVE MEANS IS OPERATED TO BLOCK DELIVERY OF PRESSURE INTO SAID CHAMBER AND THEREBY PROVIDE FOR OPENING OF BOTH THE EXPIRATION VALVE AND THE EXHAUST VALVE DURING EXPANSION OF THE BELLOWS AND TO CLOSE SAID PORTAGE WHEN THE VALVE MEANS PASSES PASSAGE INTO THE CHAMBER. 